1. Field of the Invention
The present invention relates to the calibration of vector network analyzers in general and in particular to an automatic calibration apparatus therefor which does not require the use of "perfect" calibration standards.
2. Description of the Related Art
Microwave and RF vector network analyzers (VNA) require calibration to enhance the accuracy of the system. Typically the calibration consists of measuring known "perfect" standards and transferring the accuracy of the standards to the VNA.
In practice, prior known calibration techniques typically require the connection of at least three standards between the test ports of a VNA as well as the pressing of a multiplicity of front panel buttons in a correct sequence. This is a time consuming process requiring a certain level of expertise. Verifying the accuracy of the calibration is also a time consuming process requiring expertise.